Analog front end (AFE) for quantization noise-limited sensor apparatus

An analog front end (AFE) for an input device includes a current conveyor and an analog-to-digital converter (ADC) switchably coupled to the current conveyor. The current conveyor is configured to receive an input signal from a plurality of sensor electrodes. The ADC generates an output value corresponding to a digital representation of the input signal when the ADC is coupled to the current conveyor. Further, the ADC may selectively adjust the output value based at least in part on a state of the ADC when the ADC is decoupled from the current conveyor. In some implementations, the ADC may include a delta-sigma modulator configured to generate an additional sample when the ADC is decoupled from the current conveyor. The ADC may determine an amount of quantization error in the output value based on the additional sample, and adjust the output value when the quantization error exceeds a threshold amount.